Helical propensity in an intrinsically disordered protein accelerates ligand binding

TY - JOUR

T1 - Helical propensity in an intrinsically disordered protein accelerates ligand binding

AU - Iesmantavicius, Vytautas

AU - Dogan, Jakob

AU - Jemth, Per

AU - Teilum, Kaare

AU - Kjærgaard, Magnus

N1 - Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

PY - 2014/2/3

Y1 - 2014/2/3

N2 - Many intrinsically disordered proteins fold upon binding to other macromolecules. The secondary structure present in the well-ordered complex is often formed transiently in the unbound state. The consequence of such transient structure for the binding process is, however, not clear. The activation domain of the activator for thyroid hormone and retinoid receptors (ACTR) is intrinsically disordered and folds upon binding to the nuclear coactivator binding domain (NCBD) of the CREB binding protein. A number of mutants was designed that selectively perturbs the amount of secondary structure in unbound ACTR without interfering with the intermolecular interactions between ACTR and NCBD. Using NMR spectroscopy and fluorescence-monitored stopped-flow kinetic measurements we show that the secondary structure content in helix 1 of ACTR indeed influences the binding kinetics. The results thus support the notion of preformed secondary structure as an important determinant for molecular recognition in intrinsically disordered proteins. Binding kinetics: Intrinsically disordered proteins frequently display transient secondary structure. But, the role of this secondary structure for the binding process is not well understood. By modulating the helical propensity of an intrinsically disordered protein domain and monitoring the structural and kinetic changes by NMR spectroscopy and stopped-flow methods, the effects on ligand binding can be deduced.

AB - Many intrinsically disordered proteins fold upon binding to other macromolecules. The secondary structure present in the well-ordered complex is often formed transiently in the unbound state. The consequence of such transient structure for the binding process is, however, not clear. The activation domain of the activator for thyroid hormone and retinoid receptors (ACTR) is intrinsically disordered and folds upon binding to the nuclear coactivator binding domain (NCBD) of the CREB binding protein. A number of mutants was designed that selectively perturbs the amount of secondary structure in unbound ACTR without interfering with the intermolecular interactions between ACTR and NCBD. Using NMR spectroscopy and fluorescence-monitored stopped-flow kinetic measurements we show that the secondary structure content in helix 1 of ACTR indeed influences the binding kinetics. The results thus support the notion of preformed secondary structure as an important determinant for molecular recognition in intrinsically disordered proteins. Binding kinetics: Intrinsically disordered proteins frequently display transient secondary structure. But, the role of this secondary structure for the binding process is not well understood. By modulating the helical propensity of an intrinsically disordered protein domain and monitoring the structural and kinetic changes by NMR spectroscopy and stopped-flow methods, the effects on ligand binding can be deduced.

U2 - 10.1002/anie.201307712

DO - 10.1002/anie.201307712

M3 - Journal article

C2 - 24449148

SN - 1521-3773

VL - 53

SP - 1548

EP - 1551

JO - Angewandte Chemie (International ed. in English)

JF - Angewandte Chemie (International ed. in English)

IS - 6

ER -